@article{DAN_1983_269_1_a8,
     author = {S. Ya. Yakubov},
     title = {Quadratic operator pencils},
     journal = {Doklady Akademii Nauk},
     pages = {39--42},
     publisher = {mathdoc},
     volume = {269},
     number = {1},
     year = {1983},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1983_269_1_a8/}
}